The x-ray head for a radiographic imaging apparatus is generally supported on some type of boom that allows the head to be properly positioned with respect to the subject being imaged and to the imaging detector. The x-ray head contains the emissive x-ray source and typically also has a number of related components that can include a collimator, controls, and guiding handles, for example. X-ray boom design is complicated by a number of factors, including the combined weight of the x-ray source and supporting components, the need to be able to flexibly position the head with the necessary rotational and translational degrees of freedom, and the requirement that the head position be stably maintained during setup and imaging procedures.
Supporting the boom for the x-ray head presents a particular challenge for mobile x-ray apparatus. Unlike conventional wall- and ceiling-mounted x-ray systems, mobile x-ray apparatus can be wheeled around the ICU or other area and brought directly to the patient's bedside. In these circumstances, the operating space for maneuvering the boom and x-ray head (for example, within the narrow space between patient beds) restricts the clinician's ability to quickly and accurately position the device for x-ray acquisition. In addition, the added weight and complexity of the head support boom and its associated hardware are factors that can add to the cost of these devices and complicate their operation and maintenance requirements. For example, where the x-ray head is mounted with a cantilevered arrangement, sufficient counterbalance mechanisms and ballast are required in the mobile x-ray cart base to allow movement by the clinician or technician. This tends to increase the overall weight of the mobile x-ray apparatus, thereby requiring more complex automated drive and steering mechanisms. These requirements, in turn, tend to increase product cost and complexity, with added risk factors related to unintended system motion.
Mobile apparatus designs in commercial use are characterized by complex, cantilevered boom designs with fixed or collapsible columns and the need for substantial counterweights, numerous supporting actuators, and fixed movement paths between spatial locations, often constrained by the mechanical design of boom components.
One concern that must be addressed in design of the support member relates to ease of positioning of the x-ray source mounted on its boom. For ease of operation under varying conditions, the technician should be able to easily position and orient the x-ray source without requiring both hands, without the need of additional tools, and without needing help from nearby personnel. This includes moving the x-ray source from its docked position used in transport to an imaging position. The mechanical problem of providing ease of positioning is complicated by the weight of the x-ray source and by its extension outward from the vertical axis.
Thus, there is a need for an x-ray head support boom that offers reduced weight, reduced parts count, and relative ease of use by the attending technician, particularly in confined areas, both for stationary x-ray systems and mobile x-ray apparatus.